//https://leetcode.cn/problems/factorial-zeros-lcci/description/

#include <iostream>
using namespace std;

int main() {
    double num = 0.0;
    cin >> num;
    int temp = (int)num;
    if ((temp + 1) - num <= 0.5)
    {
        cout << temp + 1;
    }
    else {
        cout << temp;
    }

}
